Purchased a jet ski trailer that I converted to a kayak trailer. It has the standard 4 pin (3+grd) connector and my 97 F-150 had the 7 pin.

While replacing the 7 with a 4 I shorted out the yellow left turn signal wire and blew the 40 amp fuse in the power distribution box. But replacing the fuse didn't restore either of the trailer turn signals. I had turn signals to the trailer in the beginning so I know the trailer wiring is fine.

Running lights work fine.

I've checked every single fuse in the truck I can find.....in the power distribution box and under the dash......and I'm lost as to what else it could be. I've read that some F-150's have fuses behind the passenger kick panel, mine does not.

 

You might've also popped the relay.

I'd first read your manual:

http://www.fordservicecontent.com/Fo.../97f12og1e.pdf

 

 

Why would you replace the 7 pin with a 4 pin??

They make adapters for that...

That's what I did with my 97 that only had the 7 pin. Just shove the 7 to 4 pin adapter, plug in the 4 pin to the trailer and all good...

If I recall, the turn signals have their own fuse separate from the brake lights?

Good luck!

Mitch

 

 

You should be able to get a new 7 pin wire harness that would plug into the main wire harness where the spare tire is. Or, get the 4 pin harness that would plug into the same main wire harness if you won't ever need trailer brakes.

Since the running lights work, ground is probably okay.. On the 4 pin, the brake lights and turn signals use the same 2 pins as the left and right signals. Do the trailer brake lights work?

 

Thanks for the info. No, the brake lights don't work either. I can't believe that I fried the harness because the two lines were not in contact with each other but for half a second.....doesn't seem that it was long enough to build up that much heat but maybe a new harness is the way to go..

It appears that the truck's manual is not accurate. Book says that the smaller fuse box behind the power distribution box has mini fuses in it but it actually has relays. More over, the book says that the #2 mini-fuse in that box is supposed to go to the trailer turn signals. So, I pulled all the relays and ran a bench test. All closed as they should. One or two had one ohm of resistance and the rest had none.

 

PROBLEM SOLVED. There is a mini-fuse block that is mentioned in the owners manual but not pictured. The one they pictured is not a mini-fuse block but a block behind the power distribution box that has about 6 relays in it. The block I needed to check is tucked up under the inside of the fender and doesn't show up in any photos in the owner's manual. When I finally located it, it had two fuses in it.......a 10 and a 20, just like the manual said, the 20 was blown. Hoping when it's replaced I'll have trailer turn signals.
Thanks to all for your help.

 

If you download the 97 manual from Ford, it will have the correct information in it. The info on that mini fusebox is missing from the 98 manual but the layout under the hood is the same as a 97.